1. Field of Invention
This invention relates generally to oil pumps and, more specifically, to a debris evacuation apparatus and method that is intended to extend plunger and barrel life.
2. Background of the Invention
In general terms, an oil well pumping system begins with an above-ground pumping unit, which creates the up and down pumping action that moves the oil (or other substance being pumped) out of the ground and into a flow line, from which the oil is taken to a storage tank or other such structure.
Below ground, a shaft is lined with piping known as “tubing.” Into the tubing is inserted a sucker rod, which is ultimately, indirectly, coupled at its north end to the pumping unit. Below the sucker rod are located a number of pumping system components, including the cage and, below the cage, the plunger. The plunger operates within a barrel, which barrel is positioned within the tubing.
The amount of space between the exterior surface of the plunger and the interior surface of the barrel can be as great as 0.01″. This space allows a constant passage of fluid, including debris, between the plunger exterior and the barrel interior. The debris that is contained within the fluid and that passes through the space between plunger and barrel scores the plunger and the barrel, reducing the operating life of both.
A need therefore existed for an apparatus and method that will evacuate debris from the space that is between the plunger and the barrel, so as to extend the operating life of each of these two pumping system components. The present invention addresses this need and provides other, related, advantages.